Large quantities of fly or coal ash carried by the combustion products of power plants burning pulverized coal exist throughout the country and more is being created by the operation of these plants. This accumulation creates a disposal problem and represents a waste of metal values as coal ash can contain from 7.1 to 14.3% aluminum, 2.7 to 29.0% iron, and 0.28 to 0.83% titanium by weight. Lesser amounts of other useful metals are present in coal ash.
There are existing processes for recovering some of these metals from fly ash but none are capable of recovering all of these metals. There is a need for a relatively safe and inexpensive method for separating metals from coal ash. It is an object of the present invention to provide such a method.